Factum Foundation has joined forces with the Hermandad de la Santa Caridad and the Instituto Andaluz de Patrimonio Histórico (IAPH) to digitally document two of Murillo's masterpieces: 'Milagro de la multiplicación de los panes y los peces' and 'Moisés haciendo brotar el agua de la roca de Horeb'.

In the context of the 400th anniversary of the artist's birth – an event that has triggered a number of initiatives throughout the city of Seville to celebrate and disseminate Murillo's work – these two magnificent paintings that belong to La Caridad have been the object of a major conservation project. In 2017, with the participation of the Fundación La Caixa, experts at the IAPH restored and documented the two works. Following the restoration, Factum Foundation contributed to this ambitious project by recording the paintings, including the gilded frames, with non-contact, high-resolution technologies. The information obtained will be of great value for the conservation, study and dissemination of Murillo's work.

As a result of this initial project, arranged by Casilda Ybarra from Colnaghi/Coll&Cortés, Factum Foundation aims to continue employing cutting-edge technology to document the golden age of the 17th century Sevillian Baroque, whose representatives include Murillo, Pedro Roldán and Valdés Leal, amongst others. The Hermandad de la Santa Caridad houses some of the finest examples of these artists' work.

The first phase of the documentation project consisted of scanning the surface of the two paintings. Two units of the Lucida 3D Scanner, a system specifically developed by Factum for digitising the relief of artworks for conservation purposes, were used in tandem to record both canvases – approx. 236 x 575 cm each and with a total area of over 27 m2. The recording was carried out between February 22nd and March 12th by Aliaa Ismail and Belén Jiménez, who worked in the well-equipped facilities of the IAPH with the kind help of conservators Araceli Montero, Lourdes Núñez and Rocío Magdaleno. The project was supervised by Carlos Bayod.

Each one of the two great Murillo paintings, measuring 236x575 cm, is the largest single artwork ever recorded with the Lucida 3D Scanner, and probably the first time a painting this size is 3D scanned in high resolution.

Two Lucida systems were used in tandem to record a total area of over 27 m2

The Lucida 3D Scanner is capable of capturing every detail on the surface with a resolution of 100 microns

Lucida records 'tiles of data' of 48x48 cm arranged in rows and columns, from a constant distance of 10 cm

The scanner's structural frame was adapted to reach the top of the paintings at about 3m from the floor

It was essential to guarantee the stability and verticality of the scanner throughout the process

Each scanning tile of 48x48 cm takes 1h to complete

A total of 150 scanning tiles where recorded out of the two paintings

Factum Foundation seeks to enhance the importance of recording artworks as part of their conservation

Shaded render of a section of the canvas' 3D data obtained with Lucida

Shaded render of a section of the canvas' 3D data obtained with Lucida

Shaded render of a section of the canvas' 3D data obtained with Lucida

The next step involved using high-resolution panoramic composite photography to record colour data. Each painting was captured from two different points of view, so that half of the canvas was recorded from each position. Shooting from a distance of about 6m from the painting, the lights were positioned at either side of the camera, forming an angle of about 45º with respect to the shooting trajectory. Hundreds of high-resolution photographs were taken to produce a single high-resolution file after stiching. The panoramic photography was carried out on March 12th-13th by Gabriel Scarpa with the help of Natalia Pérez Buesa.

The color recording of the paintings took two days of work at the IAPH

In addition to 3D and colour data obtained by Factum Foundation, the IAPH carried out a series of analyses on the paintings, including XR and UV. These datasets will become part of a multilayer digital file that will allow a user to view the high-resolution information from any computer screen. Understanding artworks as complex subjects composed of layers of information is at the core of Factum Foundation's approach to preservation.

The paintings were part of the temporary exhibition 'Murillo cercano. Miradas cruzadas' at the Hospital de la Caridad in Seville (March 28th to November 30th), where they could be seen up-close for the first time. When the exhibition closes, the two Murillo paintings will be installed once again in the church of San Jorge, which contains one of the most unique sets of Baroque paintings in Spain, comprising works by Valdés Leal, Pedro Roldán or Simón de Pineda.

The second phase of the project has entailed recording the two gilded wooden frames belonging to the paintings, employing high resolution photogrammetry to digitise their form, texture and color. Factum Foundation's Gabriel Scarpa and Pedro Miró worked at the IAPH on May 14-16th, where they obtained the information necessary to generate high resolution 3D models of the frames.

The frames are in the IAPH's facilities mounted on robust easels

The frames and paintings will be placed back in the church of San Jorge at the end of 2018

The recording process consisted on photographing the frames from multiple distances and points of view

Detail of one of the frames' 3D model in progress

The high resolution colour reproductions of Murillo's Milagro de la multiplicación de los panes y los peces and Moisés haciendo brotar el agua de la roca de Horeb will be presented in Seville in 2019. The two paintings will be installed at La Caridad where they will be permanently exhibited.

Colour Processing

During the recording, around 1500 photographs were taken for each painting – this facilitated a vast colour file being generated in real scale with 600ppi. The sheer size and weight of the resulting panoramic files (over 100GB) made the colour processing a difficult challenge, one that required every step being multiplied to ensure the a smoothly optimised process.

The first step was to process every image generating a specific colour profile and adjusting different parameters, such as white balance or exposure. Once the corrected images were obtained, the stitching process began in order to get a large panoramic file using a semiautomatic software like PtGUi. This software allows all control points between the images to be checked, thus generating a vast diagram (the red lines mark the limits of each image); the software also allows the careful examination of critical focus zones and the ability to fix them manually.

As a result of the vast size of both paintings, two panoramas had to be generated separately and then combined in Photoshop. The colour of this unique panoramic image was then adjusted using colour checker in the centre and all corners. This tool assists the controlling and matching of the real colour and the digital colour file; this also proved crucial for the printing process.